title: Characterization of the cytochrome b (cyt b) gene from Monilinia species causing brown rot of stone and pome fruit and its significance in the development of QoI resistance.
abstract: BACKGROUND
  Quinone outside inhibitor (QoI) resistance as a consequence of point mutations in the cytochrome b (cyt b) gene has been reported in numerous plant pathogenic fungi. To examine the potential for QoI resistance development in those Monilinia species causing brown rot of stone and pome fruits [Monilinia fructicola (G Winter) Honey, M. laxa (Aderhold & Ruhland) Honey and M. fructigena (Aderhold & Ruhland) Honey], an examination was made of the sequence and exon/intron structure of their cyt b genes for the presence of any point mutations and/or introns commonly associated with resistance to QoIs in fungal plant pathogens.
  
  
  RESULTS
  None of the point mutations typically linked to QoI resistance was present in any of the Monilinia isolates examined. Furthermore, the cyt b genes from M. fructicola and M. laxa, but not M. fructigena, possessed a group-I-like intron directly after codon 143. Based on the results obtained, a simple PCR assay using a single primer pair was developed, allowing discrimination between the three Monilinia species without the need for culturing.
  
  
  CONCLUSIONS
  Results suggest that resistance to QoI fungicides based on the G143A mutation is not likely to occur in M. fructicola or M. laxa. Conversely, M. fructigena may be at higher risk for developing QoI resistance owing to the absence of a G143-associated intron.
authors.affiliation: Department of Plant Pathology and Plant-Microbe Biology, New York State Agricultural Experiment Station, Cornell University, Geneva, NY 14456, USA.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Hily
authors.forename: Stacy D
authors.initials: SD
authors.lastname: Singer
authors.forename: Sara M
authors.initials: SM
authors.lastname: Villani
authors.forename: Kerik D
authors.initials: KD
authors.lastname: Cox
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D045303:Cytochromes b / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D025141:Drug Resistance, Fungal; D005638:Fruit / Q000382:microbiology; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005659:Fungicides, Industrial / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology*; D027861:Prunus / Q000382:microbiology*; D011809:Quinones / Q000494:pharmacology*; D016415:Sequence Alignment
chemical_list: D005656:Fungal Proteins; D005659:Fungicides, Industrial; D011809:Quinones; D045303:Cytochromes b